In the following disclosure, positional terms such as “above” and “below” are used with reference to a gun in its normal firing position, that is, positioned to shoot “forward” (away from the shooter) in a generally horizontal plane.
Holding devices to attach, with precise positioning, an accessory device to a weapon are well-known in the art. For example, holding devices of this type are described in DE-GM 89 09 502 U1, GB 175 676 A, and, in a different field, U.S. Pat. No. 6,033,145. Holding devices of this type have many applications. One such application is to attach a precision optical-measurement accessory to a portal milling machine. In this example, the positioning of the accessory may need to be measured and adjusted several times a day depending on changes in the ambient temperature.
However, a more common application of a precision-positioning holding device is to attach an accessory, such as a telescopic sight, to a weapon, such as a rifle. Several issues may be encountered when attaching a telescopic sight to a rifle. For example, the attachment must be precise, because a divergence of the telescopic sight of only one (1) angular minute may produce an error of nine (9) cm at a distance of 300 m. Such an error can determine whether or not a target is hit successfully, especially considering the additional error introduced by the inherent spread of a sniper rifle. Another issue often encountered is that, depending on the particular situation, the telescopic sight must be easy to remove and reattach. Also, the holding device should be sufficiently strong and resilient so as to not wear out over time, that is, so as to provide a reproducible attachment of the telescopic sight to the rifle even after repeatedly detaching and reattaching the telescopic sight. Finally, the holding device should be able to withstand a reasonable amount of mechanical loading without misadjustment.
Telescopic sights used by the military are typically light in weight. Thus, if only a telescopic sight is to be mounted to the rifle, then a holding device having moderate strength and resilience should be sufficient. However, the holding device may be required to attach additional accessories that are coupled with the telescopic sight, such as night vision apparatus, distance-measuring equipment and many other options. In the latter case, the combined weight of all the accessories can easily exceed 2 kilograms, thereby requiring the use of a sufficiently strong and resilient holding device.
Holding devices traditionally used to attach telescopic sights on sniper rifles of the former East Germany are not adequate for securing the combined set of accessories described previously. In a typical holding device, a fixing pin is arranged on the barrel above the cartridge chamber and an opposite engagement formation sits on the bridge above the rear side of the magazine chamber. The fixing pin and the engagement formation are attached to the bottom side of the telescopic sight. The telescopic sight is initially held transverse to the axis of the bore of the rifle in a generally horizontal plane. The fixing pin is located with its vertical axis over a fixing bore. The fixing pin is introduced into the bore all the way to the back stop and the telescopic sight is then swiveled into a position parallel to the axis of the bore. Through this motion, ridges on the fixing pin engage underneath counter-ridges in the fixing bore, thus pressing the fixing pin to the bottom part of the holding device. At the same time, the engagement formation on the telescopic sight snaps into a counter-formation on the rifle, and complementary inclined recesses and projections press the engagement formation to the bottom part of the holding device. These ridges/counter-ridges and recesses/projections guide the attachment of the telescopic sight to the firearm and hold these pieces firmly together. The engagement formation has some amount of longitudinal clearance, which, however, does not negatively affect the alignment of the optical axis of the telescopic sight and the axis of the bore of the firearm.
The known holding devices described above are constructed so that they can be assembled and disassembled quickly. Moreover, the distance between the pin and the engagement formation typically has a tight tolerance. As a result, these holding devices are usually costly to manufacture as they require a considerable amount of manual work to fabricate their constituent components. Furthermore, if the telescopic sight is coupled with the above-mentioned accessories (e.g., night vision devices, distance-measuring equipment, etc.), then the increased surface pressure may cause the holding device to fatigue more quickly than expected.
To increase the strength and resilience of a traditional holding device, it may be possible to enlarge its constituent components by a proportional amount. However, this would result in a more costly, heavier design.